User encryption of content continues to be virtually non-existent. For instance while dozens of attempts have been made to provide for email encryption, a vast majority of emails are still sent without end to end encryption. The advent of social networking has worsened the situation. People, especially the younger generation have grown used to putting sensitive personal data on social networking sites. While most of these sites have some basic mechanism of determining who can see what content, it is controlled by the particular social network. So for instance a teenager has to remember who is in their ‘friends’ list on each social networking site they use. Or consider blogs and similar tools like wikis. In general something you write on your blog or enter into a wiki is available to absolutely everyone.
We define user centered privacy, as privacy that is enforced by the user, not by the particular email, social network, wiki or blog they use. In user centered privacy, the user can choose, regardless of which system they are on, to encrypt data in a fashion that it can only be viewed by those allowed to view it.